I could swear that in the early 1990’s the plan for the new Star Wars movies included Episodes 7, 8, and 9 too. Was this just a rumour at the time that was published in some magazines or did I dream the whole thing up or again was there actually a plan to do three other movies?
I also remember this. As I recall, 7-9 were to be based on the Timothy Zahn trilogy.
I read it in Time when The Empire Strikes Back came out as “Episode V”: Lucas explained he intended a nine-part series of three trilogies. But since Revenge of the Sith, he has given no indication he plans any more films.
I’m torn. On the one hand, I think the Thrawn trilogy would make three absolutely awesome movies. On the other hand, I don’t think I want Lucas to get anywhere closer than ‘Executive Producer’ to them.
After considerable research, a guy wrote an ebook documenting the development of Star Wars - a must read for any fan - that covers this an a LOT more.
I’ll see if I can find it.
My mom clipped a newspaper article about this for me in the early '90s, and IIRC Lucas reaffirmed it right around the time the production began on the prequel trilogy in ~97. Since then he has shot it down and, if I’m not mistaken, even denies ever saying it.
Both Time and Newsweek had similar articles about a “trilogy of trilogies” when Episode V came out in 1980.
Lucas now claims that he never said anything about episodes 7-9.
Wikipedia has a lot of detail on this, of course - you can read this in the entries for Star Wars and Star Wars sequel trilogy. He did say in the '90s that he thought the story might take as many as nine movies, but IMO he was just blustering - pretending like he’d always intended to make six movies or more when that wasn’t actually the case.
One thing I remember about the original interview (which I can’t find) where explained that “Star Wars: A New Hope” was movie 4 of 9 was that the only characters to appear in all nine movies would be C3PO and R2D2.
Here it is
The Secret History of Star Wars
Find out about Luke’s Father and Brother
The Spiritual Side of the Jedis
and much more
What you want is in Chapter VII: Demons and Angels
I remember references to nine episodes back in the 1980s too.
Or even twelve episodes.
http://www.darklordscouncil.com/forums/archive/index.php4/t-61.html
Courtesy of MAD magazine 1982.
Although intended humorously, it is interesting to note that they got one prediction right, sort of.
Chapter 5 of my link talks about cutting it from 12 to 9
Siskel and Ebert mention it in their Return of the Jedi review.
Agreed, after seeing the prequel trilogy it’s clear that even though he thinks he knows what he’s doing…he really has no idea.
I don’t think you read the link 
The last bit is rather prescient, only missing by one generation: